[THEFERMANATOR]

What year was your old 175 JOHNSON? As to prop VS flywheel differences, a good example could be the 235HP EVINRUDE basically became a 175HP engine when they went to prop shaft ratings. On the other hand some engines stayed the same as a 150 EVINRUDE stayed the 150. On average you expect to see a 10-18% loss. And if your JOHNSON was made after 86 it was propshaft rated, and your 200 MERC became a 175 when MERC went to propshaft ratings. So you stayed at teh same power levels. And you should be seeing more than 5100 out of that old 2.4L if you want it to perform well. 5100 is lugging it down quite a bit. 5300-5500 would be alot better for it. And if you're after performance, ditch teh aluminum prop, and go with a stainless. I would reccomened a 17 pitch stainless 3 blade prop.